A specialized passenger carriage equipped with a set of driving controls, windows, and a warning bell or whistle at one end. Through a system of mechanical linkages or cables running under the floor, the engineer sitting in this car can operate the regulator and brakes of the steam locomotive pushing from behind, eliminating the need to turn the train around at branch line terminals.
Heard on the job
We'll take the autocoach down the branch line so we don't have to mess with the turntable at the junction.